title: Estrogen oversees the maintenance of the female genetic program in terminally differentiated gonochorists.
abstract: The sexual plasticity of the gonads is not retained after the completion of sex differentiation in vertebrates, except in some hermaphroditic species. Here, we report that the depletion of estradiol-17β (E2) by aromatase inhibitors (AI) for up to six months resulted in a functional female-to-male sex reversal in sexually-mature adults of two gonochoristic fish species, Nile tilapia and medaka. The sex-reversed fish showed a typical male pattern of E2 and androgen levels, secondary sexual characteristics, and male-like sex behavior, producing fertile sperm. Conversely, co-treatment of E2 inhibited AI-induced sex reversal. In situ hybridization of medaka gonads during AI-induced sex reversal indicated that cysts on the dorsal side of the adult ovaries are the origin of germ cells and Sertoli cells in the newly formed testicular tissue. Gonochoristic fish maintain their sexual plasticity until adulthood and E2 plays a critical role in maintaining the female phenotype.
authors.affiliation: 1] Solution-Oriented Research for Science and Technology (SORST) [2] Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan [3] [4].
authors.forename: B
authors.initials: B
authors.lastname: Paul-Prasanth
authors.forename: R K
authors.initials: RK
authors.lastname: Bhandari
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: R
authors.initials: R
authors.lastname: Horiguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Nakamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Shibata
authors.forename: F
authors.initials: F
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D015415:Biomarkers; D002454:Cell Differentiation; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology; D004967:Estrogens / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D005399:Fishes / Q000235:genetics* / Q000378:metabolism*; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis; D006066:Gonads / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism; D008297:Male; D010641:Phenotype; D012098:Reproduction; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000187:drug effects / Q000502:physiology*; D013737:Testis / Q000502:physiology
chemical_list: D015415:Biomarkers; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D004958:Estradiol